Triwall Hydrocarbon Well Recovery System and Method

ABSTRACT

A buoyant ball assisted hydrostatic lift system and method comprises a second annulus formed between a well bore and an outer pipe within the well bore, and a first annulus formed between the outer pipe and an inner pipe. The system includes a seal disposed on the second annulus on at least a top end and a bottom end thereof with respect to the earth&#39;s surface. The seal is configured to prevent a fluid flow there through and preserve a condition of the well bore and the outer pipe and protect the environment against well perforations. The system also includes buoyant balls entrained in a first fluid in one of the annuli and an entrained column of the buoyant balls in the first fluid in one of the annuli, an aggregate weight thereof configured to entrain the balls and the first fluid into a second fluid in the inner pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of and claims the benefit ofthe priority date of earlier filed U.S. Non-Provisional Utilityapplication Ser. No. 14/085,600, filed Nov. 20, 2013 for Rod D. Smith,which claims the benefit of earlier filed U.S. Non-Provisional Utilityapplication Ser. No. 13/706,150, filed Dec. 5, 2012 for Rod D. Smith,which claims the benefit of earlier filed U.S. Non-Provisional patentapplication Ser. No. 13/568,471, now U.S. Pat. No. 8,430,172 filed Aug.7, 2012 for Rod D. Smith et al. which claims the benefit of earlierfiled U.S. Provisional Patent Application Ser. No. 61/659,394, filedJun. 13, 2012 for Rod D. Smith, each incorporated herein by reference inits entirety.

BACKGROUND AND FIELD OF INVENTION

By some measures, a total of about 707,000 barrels of oil per day wereproduced in the United States in 1998 using Enhanced Oil Recovery (EOR)methods, accounting for about 12% of total national crude oilproduction. Methods vary including thermal (steam and hot water), gas(carbon dioxide, nitrogen), chemical and even microbial enhanced oilproduction. The carbon dioxide, natural gas and nitrogen EOR consumemuch more electric power per barrel of oil produced than thermal EORmethods. Current electric power requirements for gas EOR for pumpingfluids from the wells (including substantial amounts of water),separating product etc consumes an estimated 1.5 million hp (1,230 MW).Therefore, opportunities are plentiful for business development forpetroleum producers and utilities to come up with more effective andless expensive methods of EOR.

In the United States of America, one out of every six barrels of crudeoil produced comes from a marginal oil well and over 85 percent of thetotal number of U.S. oil wells are now classified as stripper wells. Astripper well or marginal well is an oil or gas well that is nearing theend of its economically useful life. There are over 420,000 of thesewells in the United States, and together they produce nearly 915,000barrels (145,500 m³) of oil per day, 18 percent of U.S. production.However, stripper wells may suffer from casing perforations due tocorrosion and extended use. Perforations further complicate productionfor stripper wells in terms of pressure maintenance and loss ofproduction through the perforations.

Subterranean wells may be drilled primarily to extract fluids such aswater, hydrocarbon liquids and hydrocarbon gases. These fluids existwithin the earth to depths in excess of 5000 meters below the earth'ssurface. Subterranean traps, called reservoirs, accumulate the fluids insufficient quantities to make their recovery economically viable.Whether or not a fluid of interest can reach the earth's surface withoutaid may be a function of the potential energy of the fluid in thereservoir, reservoir driver mechanisms, reservoir rock characteristics,near wellbore rock characteristics, physical properties of the desiredfluid and associated fluids, depth of the reservoir, wellboreconfiguration, operating conditions of the surface facilities receivingfluids and the stage of the reservoir's depletion.

Many wells in the early stages of production are capable of producingfluids with little more than a pipe to connect the reservoir withsurface facilities, as energy from the reservoir and changing fluidcharacteristics can lift desired fluids to the surface. However, toimprove the economics of a well, it may be necessary to increase theproduction rate and maximize the recovery of the desired fluid(s) fromthe well. Transportation of fluids from the reservoir to the surface,that is well bore dynamics, is one of the variables of the well that canbe controlled and has a major impact on the economics of a well.

One can improve well bore dynamics by two methods: 1) designing awellbore configuration that optimizes and improves the flowcharacteristics of the fluid in the well bore conduit, and/or 2) aidingin lifting the fluid to surface with artificial lift. Artificial liftcan significantly improve production early in life of many wells and maybe the only option for wells operating in the later stages of depletion.There are numerous systems of artificial lift available and operatingthroughout the world. The more common systems are reciprocating rodstring and plunger pumps, rotating rod strings and progressive cavitypumps, electric submersible multi-stage centrifugal pump, jet pumps,hydraulic pumps and gas lift systems. To fit in the category ofartificial lift, additional energy not from the producing formation orfluids input into the well bore is added to help lift fluids in theliquid paths to the earth's surface. With the depletion of the world'sfluid reserves, there is a long felt need to develop an artificial liftsystem and method that is both economical and practical.

SUMMARY OF THE INVENTION

A buoyant ball assisted hydrostatic lift system and method lifts a fluidfrom an enclosed subterranean reservoir to the earth's surface. Thesystem comprises a second annulus formed between a well bore and anouter pipe within the well bore, and a first annulus formed between theouter pipe and an inner pipe. The system also includes a seal or apacker formed or disposed on the second annulus on at least a top endand a bottom end thereof with respect to the earth's surface, the sealconfigured to prevent a fluid flow there through and preserve acondition of the well bore and the outer pipe. Some disclosed systemsinclude only the second annulus and the seal or packer at the top andbottom ends thereof. The system also includes a plurality of buoyantballs entrained in a first fluid in one of the annuli, the ballsconfigured to at least one of displace a fluid mass and have a surfacefriction moving in the first fluid therein. The system additionallyincludes an entrained column of the buoyant balls in the first fluid inone of the annuli, an aggregate weight thereof configured to entrain theballs and the first fluid into a second fluid in the inner pipe.

The disclosed system also includes a plurality of annuli formed betweenan encased well bore and an outer pipe within the well bore and an innerpipe drill string within the outer pipe. The system also includes acolumn of a plurality of buoyant balls in the plurality of annuli, aweight thereof configured to entrain the buoyant balls into a firstfluid in the plurality of annuli and an aggregate weight of the columnand the first fluid configured to entrain the column and first fluidinto a second fluid in the inner pipe drill string. The system furtherincludes an increased rise velocity of the buoyant balls and the secondfluid to the surface via the inner pipe drill string based on anincrease in a radius of each buoyant ball in relation to a smallerradius and a slower velocity of the buoyant balls in the first fluid.

A method for lifting petroleum fluid(s) from an enclosed subterraneanreservoir to the earth's surface is disclosed. The method includesforming a plurality of annuli between an encased well bore and an outerpipe within the well bore and an inner pipe within the outer pipe, afirst annulus defined between the inner pipe and the outer pipe and asecond annulus defined between the encased well bore and the outer pipe.The method also includes forming or disposing a seal or a packer on thesecond annulus on at least a top end and a bottom end thereof withrespect to the earth's surface, the seal configured to prevent a fluidflow there through and preserve a condition of the well bore and theouter pipe. Some disclosed methods include forming only the secondannulus and the seal or packer at the top and bottom ends thereof. Themethod additionally includes creating a column of a plurality of buoyantballs in the plurality of annuli, a weight thereof configured to entrainthe buoyant balls into a first fluid in the plurality of annuli. Themethod further includes entraining the column of buoyant balls and thefirst fluid in the second annulus via the weight thereof and entrainingthe buoyant balls and the first fluid into a second fluid in the innerpipe via an aggregate weight thereof.

Other aspects and advantages of embodiments of the disclosure willbecome apparent from the following detailed description, taken inconjunction with the accompanying drawings, illustrated by way ofexample of the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a buoyant ball assisted hydrostaticlift system comprising a static pressurized column of buoyant balls inaccordance with an embodiment of the present disclosure.

FIG. 2 is a block diagram of a method for buoyant ball assistedhydrostatic lift in accordance with an embodiment of the presentdisclosure.

FIG. 3 is a cross sectional view of a buoyant ball recovery system inaccordance with an embodiment of the present disclosure.

FIG. 4 is a cross sectional view of a buoyant ball recovery system wherea ball hopper is vented in accordance with an embodiment of the presentdisclosure.

FIG. 5 is a cross sectional view of a buoyant ball recovery system wherethe balls enter the pipe string in accordance with an embodiment of thepresent disclosure.

FIG. 6 is a cross sectional view of a buoyant ball recovery system wherethe hopper is filled with liquid in accordance with an embodiment of thepresent disclosure.

FIG. 7 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising an entrained column of buoyant balls in a fluidin accordance with an embodiment of the present disclosure.

FIG. 8 is a cross sectional view of a controlled rise velocity buoyantball assisted hydrocarbon lift system comprising an entrained column ofbuoyant balls in a fluid in accordance with an embodiment of the presentdisclosure.

FIG. 9 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising a second annulus and a space for buoyant ballreturn to the earth's surface with lifted petroleum in accordance withan embodiment of the present disclosure.

FIG. 10 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising a second and a first annulus and an inner pipefor buoyant ball return to the earth's surface with lifted petroleum inaccordance with an embodiment of the present disclosure.

FIG. 11 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising a second and a first annulus for buoyant ballreturn to the earth's surface with lifted petroleum in accordance withan embodiment of the present disclosure.

FIG. 12 is a block diagram of a triwall method for buoyant ball assistedhydrostatic lift in accordance with an embodiment of the presentdisclosure.

Throughout the description, similar and same reference numbers may beused to identify similar and same elements depicted in multipleembodiments. Although specific embodiments of the invention have beendescribed and illustrated, the invention is not to be limited to thespecific forms or arrangements of parts so described and illustrated.The scope of the invention is to be defined by the claims appendedhereto and their equivalents.

DETAILED DESCRIPTION

Reference will now be made to exemplary embodiments illustrated in thedrawings and specific language will be used herein to describe the same.It will nevertheless be understood that no limitation of the scope ofthe disclosure is thereby intended. Alterations and furthermodifications of the inventive features illustrated herein andadditional applications of the principles of the inventions asillustrated herein, which would occur to one skilled in the relevant artand having possession of this disclosure, are to be considered withinthe scope of the invention.

An embodiment of the present disclosure includes inserting an outer pipeand pipe string into an existing well bore to recover the oil from astripper well. This is especially advantageous when the existing wellbore is damaged through rust, ground settling or through use and thewell is no longer producing. Environmental concerns associated withperforations in well bores in stripper wells may close a stripper welldue to the cost of addressing the perforations. However, in newer wellsa second annulus for recovery is created between the well bore and theouter pipe. Oil from the well may therefore be recovered through thepipe string, through a first annulus between the pipe string and theouter pipe or through a second annulus between the well bore and theouter pipe.

Present best known methods for well recovery may include artificial liftvia a high pressure source at the surface of a well to inject gas downan annulus and into a tubing bore. The compressed gas may be injectedinto the product stream through valves and may create an aeration orbubbling effect in the liquid column. The gas bubbles may expand as theyrise to the surface, displacing liquid around them. This may decreasethe density and weight of the fluid and create a differential pressurebetween the reservoir and the well bore and allow the well to produce atits optimum rate. However, the recovery and necessary recompression ofgases used for lifting is expensive and cumbersome. There is a long feltneed in the market of hydrostatic artificial lift systems for a systemand method that is both economical and practical without the expensiveuse of gases.

The term ‘well bore’ used in the present disclosure refers to a holethat is drilled to aid in the exploration and recovery of naturalresources including oil, gas or water. A wellbore is the actual holethat forms the well. A wellbore can be encased by materials such assteel, metal and cement, and a combination thereof or it may be uncased.In the present disclosure, the wellbore is encased and forms a thirdwall with an inner pipe and an outer pipe within the well bore. The term‘pipe string’ as used throughout the present disclosure defines a columnor string of pipe that transmits the lifting and/or drilling mechanismsand is therefore interchangeable with the term ‘drill string’ alsocommonly used in the art. The term ‘annulus’ used throughout thedisclosure defines a ring of space between a well bore inner wall and apipe string outer wall where the pipe string is positioned within thewell bore. The term ‘fluid’ as used throughout the present disclosuredefines both a gas and a liquid. The term ‘ball’ as used throughout thepresent disclosure may refer to circular, semi-circular, spherical andother geometrical bead-like or bubble-like devices having rigid orsemi-rigid walls and various sizes, shapes, porosities, specificgravities and various configurations including dimples, cavities(external and internal), recesses and the like. The term ‘entrainment’may include both an entraining fluid and the buoyant objects entrainedtherein. Also the terms ‘specific gravity’ and ‘mass density’ arerelational through the mass of a fluid in relation to water. The term‘rise velocity’ may refer to vertical and/or helical and/or horizontalvelocity as a ball or sphere is rising in a fluid even though the ballor sphere may take a zigzag-like path there through. Therefore, the‘rise velocity’ may be a velocity of the ball or sphere with a verticalspatial component opposing gravity relative to the fluid surrounding itrather than relative to the reservoir and/or the pipe thereof.

The purpose of the disclosed apparatus, system and method is to improvethe volume of discharged fluids flowing from a well bore. In thealternative, if the well is within equilibrium and can no longernaturally flow, the disclosed process may initiate natural flow again.This is accomplished by changing the hydrostatic pressure within a fluidcolumn through a mechanism of displacing fluid mass with buoyant ballssharing the space within the casing in a flowing well. This reduction inhydrostatic pressure may increase the net amount of fluids flowing in agiven increment of time.

One embodiment of the disclosure takes advantage of the down pipe thatis normally used to contain the flow of fluids to the surface and usesit as a conduit to transfer the buoyant balls down the bore hole to adesired depth. To facilitate the process of getting the balls to thebottom of the pipe, gas pressure is used to push down the water table inthis center pipe (aka pipe string) to varying depths forming a gascolumn. As an example, at approximately a 5,000 foot level, if the watertable ascended from the reservoir to the top (or the surface) of thatpipe, and if there was no more natural reservoir pressure to push theliquid beyond the surface, it may take approximately (depending on thespecific gravity of the liquid) 2200 psi of gas pressure to push thewater table that was at the surface all the way down the pipe to the5,000 foot predetermined level.

In an embodiment of the disclosure, the gas does not exit the bottom ofpipe string, but instead, only enough pressure is administered to takethe water table down to a very short distance from the end of the pipe.This creates a hollow void of steady state gas pressure occupying theinternal volume of the pipe all the way back up to the surface. Incontrast, the annulus between the pipe string and the well bore could befull of liquid from the reservoir to any point, all the way up to thesurface.

Embodiments of the disclosure include small buoyant balls fed into thepipe string. Under the force of gravity, the balls may fall all the waydown to the water table 5,000 feet below. Since the balls are buoyant,they may float on the water table at the bottom of the pipe. As theaccumulated amount of buoyant balls land on top of each other, theaggregated weight will eventually push the lower balls down into theliquid until they reach the end of the pipe and start their ascension upthe annulus entrained in the fluid(s) of the reservoir.

As the volume of balls increase in the annulus, the hydrostatic pressurehoused in the annulus may start decreasing. The resisting force that thecolumn is putting on the reservoir starts to lower and the spreadbetween the reservoir's pressure and the column resisting hydrostaticpressure gets wider. This increase in differential pressure may allowthe well to start flowing again, or increase the volume of a well thatis currently flowing. The annulus may thus be used to discharge the flowcoming to the surface verses the concentric pipe that is conventionallyused as a gas column. A disclosed mechanism gathers these buoyant ballsat the surface and puts them in an apparatus that allows them toovercome the pressure required to reenter the gas column describedearlier.

FIG. 1 is a cross sectional view of a buoyant ball assisted hydrostaticlift system comprising a static pressurized column of buoyant balls inaccordance with an embodiment of the present disclosure. The disclosedbuoyant ball assisted hydrostatic lift system 100 lifts a fluid 105 froman enclosed subterranean reservoir to the earth's surface 110. Thedisclosed system 100 includes a pipe string 115 configured at a steadystate gas pressure with any quiescent gas escape offset by an equal gasinput. The system also includes a plurality of buoyant balls 120 in thepipe string 115, the balls configured to at least one of displace afluid mass 105 and have a surface friction moving in a fluid 105therein. The surface friction may come from a design and/or a type ofcovering on the buoyant ball's surface as disclosed herein. Materialsand designs having larger surface friction may increase the hydrostaticpressure differential as discussed herein. Conversely, materials anddesigns having less surface friction may decrease the hydrostaticpressure differential. Any design increasing the surface area of abuoyant ball may increase its surface friction and therefore increasethe pressure differential in the annulus or vice versa in the pipestring. The pressure differential (pressure loss) may result from aheating the fluid(s) due to the surface friction of the entrained ballscausing a net loss of energy in the enclosed system including thepresent disclosure and the well thereof. The system 100 additionallyincludes a column 125 of the buoyant balls 120 in the pipe string 115,an aggregate weight of the balls 120 in the column 125 configured toentrain the balls 120 into a fluid 105 in an annulus 130 formed with anouter bore pipe 135. The system further includes a hydrostatic pressuredifferential lifting the entrained balls in the annulus 130 with respectto the reservoir via the buoyant balls 120, the pressure differentialconfigured to lift the fluid 105 in the annulus 130 to the surface 110.A ball reservoir 140 and a recovery reservoir 145 are also depicted.Water 150 may be present in the reservoir and lifted into the recoveryreservoir 145 via the disclosed system and method.

A vice versa embodiment of the disclosed hydrostatic lift system whereinthe steady state gas pressure and the column of buoyant balls are viceversa disposed in the annulus and an entrainment comprising theentraining fluid and the entrained buoyant balls is vice versa disposedin the pipe string, enables a hydrostatic pressure differential in thepipe string to lift the entrainment to the earth's surface via the pipestring. The embodiment includes an annulus pipe string configured at asteady state gas pressure with any quiescent gas escape offset by anequal gas input. The system also includes a plurality of buoyant ballsin the annulus; the balls configured to at least one of displace a fluidmass and have a surface friction moving in a fluid therein. The systemadditionally includes a column of the buoyant balls in the annulus, anaggregate weight of the balls in the column configured to entrain theballs into a fluid in a pipe string positioned within an outer borepipe. The system further includes a hydrostatic pressure differential inthe pipe string with respect to the reservoir via the buoyant balls, thepressure configured to lift a fluid in the pipe string to the surface.

Another embodiment of the disclosed hydrostatic lift system includesbuoyant balls 120 of a specific gravity less than a ratio of 1 inrelation to the specific gravity of a fluid in the annulus 130. Also,the steady state gas pressure in the pipe string 115 forces a watertable in the pipe string 115 submerged in the reservoir below thesurface 110 and proximal to a bottom end of the pipe string submerged inthe reservoir. Additionally, the column of buoyant balls 125 forms underan aggregate weight of the buoyant balls 120 and extends from a bottomend of the pipe string 115 to a column height 154 greater than a heightof the fluid 156 in the string pipe 115 and the annulus 130. In otherwords, a product of the ball density with the height of ball column 154and gravity may be greater than a product of the fluid density with theheight of fluid 156 and gravity. Ball density may be less than fluiddensity and gravity cancels out so the height of the column may begreater than the height of the fluid (Hc>>Hf). Embodiments includevarious column heights where balls of greater density and weight allowshorter columns able to entrain the balls in the fluid(s). Also, thehydrostatic pressure is a product of gravity acting on a fluid densityof any fluids in the pipe string 115 and the annulus displaced by theaggregate volume of the buoyant balls 120 therein and the height of thefluids from a confluence of the balls in the fluids to an overflow ofthe annulus 130 at the surface 110 into a catch reservoir 145. The fluidin the disclosed system may comprise at least one of water and apetroleum fluid.

In an embodiment of the disclosed hydrostatic lift system, the surfacefriction of the buoyant balls 120 moving through the fluid(s) 105creates a loss of hydrostatic pressure in the annulus 130 and creates alift of the fluid(s) 105 at a greater hydrostatic pressure in thesubterranean reservoir to the surface 110 through the annulus 130. Froma conservation of energy perspective of the closed system 100, the lossof potential energy in the annulus 130 due to the friction of the balls120 moving there through create a pressure loss which lifts the fluid(s)in the annulus.

Embodiments of the hydrostatic lift system may further include areservoir 140 of the buoyant balls 120, the reservoir 140 disposedadjacent a top of the pipe string 115 proximal the surface 110, thereservoir 140 configured to provide buoyant balls 120 for the column 125of the buoyant balls 120 in the pipe string 115 at the steady state gaspressure. Also, a catch reservoir 145 may be disposed adjacent a top ofthe annulus 130 proximal the surface 110, the reservoir 145 configuredto provide a catch for the lifted fluid(s) 105 and 150 and the buoyantballs 120. Additionally, a recovery hopper and a series of valves(depicted in FIG. 3-6) may be configured to separate the buoyant balls120 from the fluid(s) 105 and 150 rising to the surface 110 into thecatch reservoir 145 at atmospheric pressure.

FIG. 2 is a block diagram of a method for buoyant ball assistedhydrostatic lift in accordance with an embodiment of the presentdisclosure. The disclosed method includes providing 310 a pipe stringconfigured at a steady state gas pressure with a quiescent gas escapeoffset by an equal gas input. The method also includes providing 320 aplurality of buoyant balls in the pipe string, the balls configured toat least one of displace a fluid mass and have a surface friction movingin a fluid therein. The method additionally includes providing 330 acolumn of the buoyant balls in the pipe string, an aggregate weight ofthe balls in the column configured to entrain the balls into a fluid inan annulus formed with an outer bore pipe. The method further includescreating 340 a hydrostatic pressure differential in the annulus withrespect to the reservoir via the buoyant balls, the pressure configuredto lift a fluid in the annulus to the surface. The disclosed method mayyet include recovering 350 the buoyant balls from the fluid lifted tothe surface in a recovery reservoir at atmospheric pressure.

An embodiment of the hydrostatic lift method includes forcing a watertable in the pipe string submerged in the pipe string below the surfaceand proximal to a bottom end of the pipe string submerged in thereservoir via the steady state gas pressure. Also, the buoyant balls mayprovide an aggregate volume greater than a volume of the annulus. Thebuoyant balls may also form a column extending from a bottom end of thepipe string to a column height greater than a height of the fluid in thepipe string and the annulus. A height of the buoyant balls greater thana combined height of the pipe string and the annulus may be required forthe balls to be entrained in the fluid(s) of the annulus. Also, ahydrostatic pressure differential created in the annulus with respect tothe reservoir via the buoyant balls further comprises displacing avolume of fluids in the annulus and the pipe string from a bottom of thepipe string to an overflow of the annulus at the surface into a catchreservoir 145.

An embodiment of the hydrostatic lift method may further compriseproviding a reservoir of the buoyant balls 140, the reservoir 140disposed adjacent a top of the pipe string proximal the surface, thereservoir 140 configured to provide buoyant balls for the column of thebuoyant balls in the pipe string at the steady state gas pressure. Acatch reservoir 145 may be disposed adjacent a top of the annulusproximal the surface, the reservoir configured to provide a catch forthe lifted fluid(s) and the buoyant balls. Recovering the buoyant ballsfrom the fluid lifted to the surface in a recovery reservoir maycomprise separating the buoyant balls from the fluid via a series ofvalves. Also, in order to reintroduce the buoyant balls into the columnof buoyant balls in the pipe string, a ball reservoir may be disposedadjacent a top of the pipe string proximal the surface, the reservoirconfigured at the steady state gas pressure.

FIG. 3 is a cross sectional view of a buoyant ball recovery system inaccordance with an embodiment of the present disclosure. The disclosedbuoyant ball assisted hydrostatic lift system 100 lifts a fluid 105 and150 from an enclosed subterranean reservoir to the earth's surface 110.The disclosed system 100 includes a pipe string 115 configured at asteady state gas pressure with any quiescent gas escape offset by anequal gas input. The system also includes a plurality of buoyant balls120 in the pipe string 115, the balls configured to at least one ofdisplace a fluid mass 105/150 and have a surface friction moving in thefluid(s) therein. The system 100 additionally includes a column 125 ofthe buoyant balls 120 in the pipe string 115, an aggregate weight of theballs 120 in the column 125 configured to entrain the balls 120 into afluid 105/150 in an annulus 130 formed with an outer bore pipe 135.Embodiments of the present disclosure include various column heightswhere balls of greater density and weight allow shorter columns of ballsin the pipe string able to entrain the balls in the fluid(s). The systemfurther includes a hydrostatic pressure differential in the annulus 130with respect to the reservoir via the buoyant balls 120, the pressureconfigured to lift the fluid 105 in the annulus 130 to the surface 110.A ball reservoir 140 and a recovery reservoir 145 are also depicted.Water 150 may be present in the reservoir and lifted into the recoveryreservoir 145 via the disclosed system and method.

Further depicted in FIG. 3, a hopper 155 (aka hopper area) may bedisposed between the ball reservoir 145 and the pipe string 115. A valve160 may be disposed on the top of the hopper 155 that separates the ballreservoir 145 from the hopper area and a valve 165 on the bottom of thehopper 155 separates the hopper 155 from the high pressure zone therebelow in the pipe string. These valves 160 and 165 open and close toallow the balls to enter the hopper area 155 and the pipe string 115.After a pressure differential is mitigated, the balls 120 fall into thehigh pressure zone as gravity acts upon them. Valves 160 and 165 aredepicted as slide valves, however, there are many other valves that maybe used in embodiments of the present disclosure.

Again referring to FIG. 3, the lower valve 165 is closed, the vent valve170 is closed and the upper hopper valve 160 is also closed. Prior tothe upper slide valve 160 opening, a high pressure pump 175 pumps fluidinto the hopper chamber area. During the pumping sequence, the ventvalve 170 is open to the high pressure zone. As the water table rises tothe top of the hopper, the vent valve 170 to the high pressure zone isclosed. The pump 175 is turned off and at that time the upper slidevalve 160 opens. FIG. 3 highlights the hopper area full of fluid. Theupper slide valve 160 is open to the ball reservoir above it. The ventvalve to the high pressure zone is closed and the lower hopper slidevalve 165 is closed.

FIG. 4 is a cross sectional view of a buoyant ball recovery system wherea ball hopper is vented in accordance with an embodiment of the presentdisclosure. Elements depicted are similar or the same as the elementsdepicted in FIG. 3. The lower slide valve 165 is closed. The upper slidevalve 160 is open and the vent valve 170 is closed. The ball reservoir145 is full of buoyant balls 120 that are now floating on top of thefluid level. At this point, the pump 175 is turned on and the fluid ispumped out of the hopper area 155. As the fluid is pumped out, thebuoyant balls 120 float on the fluid and descend into the hopper area155.

FIG. 5 is a cross sectional view of a buoyant ball recovery system wherethe balls enter the pipe string in accordance with an embodiment of thepresent disclosure. Elements depicted are similar or the same as theelements depicted in FIG. 3. The upper valve 160 is closed separatingthe ball reservoir 145 from the hopper area 155. The pump 170 has beenturned off and the vent valve 170 to the high pressure zone is open. Thevent valve 170 vents to the high pressure zone while opened and allowsthe pressure to come to equilibrium in the hopper area 155 with the highpressure zone. At the end of this event, the lower slide valve 165 opensallowing the balls 120 to descend into the high pressure zone as gravityacts upon them. When the hopper 155 is emptied of its balls 120, thelower slide valve 165 closes again.

FIG. 6 is a cross sectional view of a buoyant ball recovery system wherethe hopper is filled with liquid in accordance with an embodiment of thepresent disclosure. Elements depicted are similar or the same as theelements depicted in FIG. 3. The lower slide valve 165 is closed. Theupper slide valve 160 is closed and the vent valve 170 leading to thehigh pressure zone is left open. The pump 175 is turned on. The pump 170is sufficiently powerful to overcome the pressure differential andproceeds to fill the hopper area again. Upon topping off the hopper area155, the pump 175 turns off, the vent valve 170 to the high pressurezone is closed and the process repeats itself starting back at FIG. 3.

FIG. 7 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising an entrained column of buoyant balls in a fluidin accordance with an embodiment of the present disclosure. Thedisclosed buoyant ball assisted hydrocarbon lift system 100 lifts apetroleum fluid 105 from an enclosed subterranean reservoir to theearth's surface 110. The disclosed system 100 includes a pipe string115. The system also includes a plurality of buoyant balls 120 in thepipe string 115, the balls configured to at least one of displace afluid mass 105 and a fluid mass 150 and have a surface friction movingin a fluid(s) therein. The column of buoyant balls is entrained in afluid 150 in the pipe string, the entrained buoyant balls 120 areconfigured to enable a pressure differential in the annulus 130 withrespect to the pressure in the reservoir and lift the entrainment viathe annulus 130 to the earth's surface 110. The embodied system may alsobe configured to vice versa entrain the column of buoyant balls 120 in afluid in the annulus 130, the entrained buoyant balls 120 are configuredto enable a pressure differential in the pipe string 115 with respect tothe pressure in the reservoir and lift the entrainment via the pipestring 115 to the earth's surface 110. The system 100 additionallyincludes a column 125 of the buoyant balls 120 in the pipe string 115,an aggregate weight of the balls 120 in the column 125 configured toentrain the balls 120 into a fluid 105 in an annulus 130 formed with anouter bore pipe 135. A ball reservoir 140 and a recovery reservoir 145are also depicted. The ball reservoir 140 may be pressurized via asurface pump which may also pressurize the entrainment in the pipestring 115. Water 150 may be present in the reservoir and lifted intothe recovery reservoir 145 via the disclosed system and method.

The buoyant balls 120 depicted in the ball reservoir 140 and in the pipestring 115 may be controlled on entry therein in order to uniformlyentrain the balls in the first fluid 150. The first fluid may be ahydrocarbon mixture of water and production by-products according torecovery demands and recycling methods employed. The balls therefore maybe throttled and may be dumped according to production schedules andflow rates required. The buoyant balls may therefore be introduced intothe ball reservoir 140 entrained in the fluid 150 or the balls may beintroduced separately into the ball reservoir 140 and entrained in thefluid 150 in the ball reservoir 140 under a pressure generated by apump. In any case, the fluid 150 may fill any space between and aroundthe buoyant balls in the column 125 such that an introduction of anadditional buoyant ball at the top of the column may push and otherwiseeject a buoyant ball at the bottom of the column 125 into the annulus130. Likewise, an introduction of an additional buoyant ball 120 intothe ball reservoir 140 when filled with entrainment comprising buoyantballs 120 and fluid(s) 150 may push and otherwise eject or release abuoyant ball 120 at the bottom of the column 125 into the annulus 130.The density of the buoyant balls depicted in the column 125 is not meantto limit the present disclosure which includes embodiments of higherdensity and lower density. Therefore, the density of the buoyant ballsentrained in the first fluid 150 may be pre-determined by the petroleumproduction rate desired and the dynamics of the hydrocarbon reservoirbeing pumped and the efficiency of the mechanisms and methods disclosedherein. Also, the pressure that may be used to entrain the buoyant ballsin the fluid 150 in the ball reservoir 140 may be predetermined. Theentrainment trajectory depicted in recovery reservoir 145 is notintended to limit the claims of the present disclosure which may includepressures above and below the pressure depicted by the trajectory of theentrainment into the recovery reservoir 145.

An embodiment of a hydrocarbon lift system is disclosed herein forlifting petroleum fluid(s) 105 and 150 from an enclosed subterraneanreservoir to the earth's surface 110, the system comprising a pluralityof buoyant balls 120 entrained in a pipe string 115 in a first fluid150, the balls 120 configured to at least one of displace a fluid massand have a surface friction moving in the first fluid 150 therein. Thesystem also includes an entrained column of the buoyant balls 120 in thepipe string 115, an aggregate weight of the balls 120 and the firstfluid 150 configured to entrain the balls 120 into a second fluid 105 inan annulus 130 formed with an outer bore pipe 135. The system furtherincludes a pressure differential in the annulus 130 with respect to thereservoir via the entrained buoyant balls 120, the pressure configuredto lift the second fluid 105 and the entrained balls 120 to enhancepetroleum production in the annulus 130 to the surface 110.

Another embodiment of the disclosed hydrocarbon lift system may furthercomprise a pump attached to the pipe string, the pump configured topressurize the first fluid and the buoyant balls entrained therein fromthe pipe string. The column of buoyant balls entrained in the firstfluid may be vice versa disposed in the annulus and the entrainedbuoyant balls in the second fluid may be vice versa disposed in the pipestring to enable a pressure differential in the pipe string to lift thebuoyant balls and the second fluid to the earth's surface. The column ofbuoyant balls forms under an aggregate weight of the buoyant balls andthe first fluid and extends from a bottom end of the pipe string to acolumn height greater than a height of the fluid in the pipe string andthe annulus.

A further embodiment of the hydrocarbon lift system for liftingpetroleum fluid(s) from an enclosed subterranean reservoir to theearth's surface, comprises a column of a plurality of buoyant balls in apipe string configured to entrain the buoyant balls into a fluid in anannulus formed with an outer bore pipe. The disclosed systemadditionally includes a pressure differential in the annulus withrespect to the reservoir via the entrained buoyant balls, the pressuredifferential configured to lift the fluid and the entrained balls in theannulus to the surface.

The column of buoyant balls may further comprise a density of buoyantballs entrained in the first fluid predetermined by a specific gravityof the first fluid and a weight of each buoyant ball therein. Also, thecolumn of buoyant balls may further comprise a density of buoyant ballsentrained in the first fluid predetermined by an external pressure onthe buoyant balls and the first fluid. Additionally, a second density ofbuoyant balls entrained in the second fluid may be based on the firstdensity and on the specific gravity of the second fluid.

Therefore, the embodiments of the hydrocarbon lift system includedherein comprise the surface friction of the buoyant balls moving throughthe fluid to create a loss of hydrostatic pressure in the annulus andcreate a lift of the fluid(s) at a lower pressure in the subterraneanreservoir to the surface through the annulus.

A hydrocarbon lift system for lifting petroleum fluid(s) from anenclosed subterranean reservoir to the earth's surface is also comprisedin an embodiment of the present disclosure. The system includes aplurality of buoyant balls configured in a column in a pipe string, theballs configured to at least one of displace a fluid mass and have asurface friction moving in a fluid. The system also includes a firstpressure configured to entrain the buoyant balls in a first fluid in thepipe string and move the buoyant balls there through into a second fluidin an annulus formed with an outer bore pipe. The system additionallyincludes a pressure differential in the annulus created via a secondpressure of the entrained buoyant balls in the second fluid with respectto a subterranean reservoir pressure, the pressure differentialconfigured to lift the second fluid to the surface and enhance petroleumproduction in the annulus.

An embodiment of the hydrocarbon lift system is disclosed wherein thecolumn of buoyant balls entrained in the first fluid is vice versadisposed in the annulus and the entrained buoyant balls in the secondfluid is vice versa disposed in the pipe string to enable a pressuredifferential in the pipe string with respect to the subterraneanpressure to lift the buoyant balls and the second fluid to the earth'ssurface.

Engineered spherical buoyant objects may be designed to optimize liftingforces and flow rates in accordance with an embodiment of the presentdisclosure. For example, a frontal area of a buoyant object may besubstantially flat. Also, cavities may be disposed on side surfaces orareas thereof, the cavities configured to capture a fluid and carry itto the surface for recovery. Additionally, wake forming ridges and/orfins may be employed to shape or detach a wake of a fluid around thebuoyant object and also control an ascent pattern including zigzag,helical and any periodic ascent or rising patterns against the force ofgravity. An engineered buoyant object, sphere or ball and otherengineered shapes of a predetermined size and shape traveling at a givenrise velocity may have a frontal effect on the liquid it is travelingupward through.

The accumulation of the liquid mass and the specific gravity of thatliquid in a vertical column may be the sum of the weight of the columnand/or the bottom psi. A buoyant object may travel faster or slowerdepending on the vertical height of the buoyant object. Considering asnapshot moment in time, focusing on the liquid just ahead of the risingobject; this liquid may have its weight as it relates to the columnweight altered to a lower value as it flows around the solid buoyantobject rising upward through the column, thus changing the psi at thebottom of the column to some degree. The buoyant object's frontal push,as well as the tailing turbulence, may distort the bottom column's psiover and above the effects of the buoyant object's lighter mass (ascompared to the liquid's specific gravity) in the column, thus affectingan effective buoyancy of the designer object.

An engineered placement of a large volume of buoyant objects in a liquidcolumn may have a large effect on the bottom column's weight or psi asthey ascend vertically through the column. The discharged flow rates mayvary based on the size and shape of each buoyant object and theaccumulated volume of the objects in relation to the liquid's volumethey are rising through. Thus, an engineered designer shape may enhanceor retard this effect also known as an effective buoyancy in anembodiment of the disclosure. The slower the buoyant object goes theless turbulence is generated on the trailing side. The faster thebuoyant object goes the more turbulence is generated on the trailingside changing the effective weight of the buoyant object due to otherforces acting on the buoyant object.

Therefore, a rise velocity of the buoyant balls may be based on abuoyant ball mass density in relation to the mass density of the fluidsentraining the buoyant balls. Where the mass density of the buoyantballs is less than the mass density of the entrainment, the buoyantballs may rise up through the entrainment. However, where the massdensity of the buoyant balls is greater than the mass density of theentrainment, the buoyant balls may sink down through the entrainment.The quantitative relation of the mass density of the buoyant balls tothe mass density of the entrainment may also determine the respectiverise or sink velocity.

A variable diameter of a buoyant ball may also affect its variable risevelocity due to a viscous drag of the entrainment on the buoyant ball.The Reynolds' number is a dimensionless number used in fluid dynamics toindicate a ratio of inertial forces to viscous forces where inertialforces appear in the numerator and viscous forces appears in thedenominator.

${Re} = {\frac{\rho \; {vL}}{\mu} = \frac{vL}{v}}$

The Reynolds' number Re is given by the hydraulic length L (variablediameter of the buoyant ball), v is the mean velocity of the buoyantball relative to the fluid, μ is the dynamic viscosity (N s/m²) of thefluid, ρ is the density of the fluid, and v (denominator) is thekinematic viscosity of the fluid. The variable diameter may be varied byan operator of the well responsible for production. The diameter may bevaried by either introducing buoyant balls of a different diameter or byincreasing the diameter of the already present balls via mechanical andchemical means.

For a sphere in a fluid, the characteristic length-scale is the variablediameter of the sphere and the characteristic velocity is that of thesphere relative to the fluid some distance away from the sphere, suchthat the motion of the sphere does not disturb that reference parcel offluid. The density and viscosity are those belonging to the fluid. Notethat purely laminar flow only exists up to Re=0.1 under this definitionand Stokes Law may apply. Stokes Law models the viscous flow around asphere and gives the viscous force or drag on a sphere per unit area.The viscous force per unit area σ, exerted by the flow on the surface onthe sphere, is in the z-direction everywhere. More strikingly, it hasalso the same value everywhere on the sphere.

The resulting terminal velocity (or settling velocity) may be given by:

$\upsilon_{s} = {\frac{2}{9}\frac{\left( {\rho_{p} - \rho_{f}} \right)}{\mu}g\mspace{14mu} R^{2}}$

where R is the radius of the buoyant ball and v_(s) is the particle'ssettling velocity (m/s) (vertically downwards if ρ_(p)>ρ_(f), upwards ifρ_(p)<ρ_(f)), g is the gravitational acceleration (m/s²), ρ_(p) is themass density of the particles (kg/m³), and ρ_(f) is the mass density ofthe fluid (kg/m³) and μ is the dynamic viscosity (N s/m²) of the fluid.

Therefore, the rise velocity of a buoyant ball may be predetermined andcontrolled in the second fluid in the inner pipe drill string by varyingor controlling respective mass densities and the radius of the buoyantballs. A ratio of the mass density of the buoyant ball in a fluid lessthan one brings a rise velocity and a ratio of the mass density of abuoyant ball in a fluid greater than one brings a falling or sinkingvelocity relative to the entrainment fluid.

Also, a terminal velocity or a settling velocity of the buoyant balls inan entrainment may vary with the square of a radius of the buoyantballs. Therefore, larger buoyant balls may have much greater risevelocities assuming a mass density difference favoring the entrainment.

Furthermore, a rise velocity of the buoyant balls relative to a first ora second entraining fluid may be predetermined by a mass density of thebuoyant balls relative to a mass density of the respective fluid.Additionally, a controlled rise velocity of the buoyant balls andtherefore the second fluid also may be predetermined by a ratio of amass density of the first fluid to a mass density of the second fluidgreater than one, the mass density of the buoyant balls cancelling outin the ratio. Said another way, the rise velocity of the buoyant ballsmay be controlled via a ratio of the mass density of the second fluid tothe mass density of the first fluid less than one.

Mathematically, for a positive rise velocity, ρ_(p)<ρ_(f1) in fluid 1and ρ_(p)<ρ_(f2) in fluid 2 but fluid 1 is denser than fluid 2 since itcontains water to a controlled amount. Therefore, the fluid 1 ratio isless than the fluid 2 ratio and therefore the following equations yieldsa number greater than one:

(ρ_(p)/ρ_(f2))/(ρ_(p)/ρ_(f1))

This allows a well operator to control the rise velocity of the buoyantballs by adjusting the buoyant ball density and diameter and byadjusting the mass density of the first fluid relative to the massdensity of the second fluid via a water component and an oil componentcontent. A mix of differing buoyant ball radii may be entrained in thefirst and second fluids to enable an average predetermined rise velocitythere through. Ratios less than one may bring a slower rise velocity ofthe buoyant balls and ratios larger than one may bring a faster risevelocity to the surface.

When the mass density of the first fluid and the second fluid areapproximately equal, then the rise velocity of the buoyant balls may becontrolled via the diameter and therefore the mass density of thebuoyant balls. The mass density of the first fluid is controlled at thesurface by the well operators. The mass density of the second fluid maybe determined by sampling or probing the well and may vary over time.Therefore the ratio of the two fluids may also be predetermined andcontrolled by the well operators to maximize buoyant ball rise velocityand production.

More specifically, a rise velocity between 22+ in/sec and 1.4 in/secbased on a buoyant ball specific gravity of 0.23 and a buoyant ball ofabout Ø¼″ or smaller. A smaller particle size, having a Reynolds numberof less than 1 may enable a rise velocity in oil of only 1.4 in/sec orless. In order to achieve 22 in/sec of rise velocity the buoyant ballmay need to be almost 1 inch in diameter, variable from the quarter inchor smaller diameter. However, at this rise velocity it may no longer bestrictly considered creeping flow (Reynolds number approximately 32) andthe drag model may be adjusted slightly to better match this type offlow.

The production of petroleum from the subterranean reservoir to theearth's surface over time is therefore increased by an increase in therise velocity of the buoyant balls which in turn produce a higherpressure differential in the lifting pipe with respect to the reservoirpressure. With an increase in rise velocity comes an increase of oilflow per period of time. The disclosed method and system also enablesflow from wells which have been furloughed for low pressure therebyincreasing production in wells which have been previously abandoned.

A mechanical bit release may remotely release the core bit from the pipestring to allow oil production through the pipe string. The drill bitmay be released before production starts because the internal diameterof the drill bit throat (2.312 in.) may not be large enough forproduction. Otherwise the bit is left in the hole. However, this metal“junks” the hole and may effectively prevents further coring. Removingor otherwise reducing the core bit in the inner pipe or pipe stringenables production through the pipe string to the surface in anembodiment of the present disclosure.

FIG. 8 is a cross sectional view of a controlled rise velocity buoyantball assisted hydrocarbon lift system comprising an entrained column ofbuoyant balls in a fluid in accordance with an embodiment of the presentdisclosure. The disclosed buoyant ball assisted hydrocarbon lift system800 lifts a petroleum fluid 105 from an enclosed subterranean reservoirto the earth's surface 110. The disclosed system 800 includes a pipestring or inner pipe 115 and an outer pipe 135. The system 800 alsoincludes a plurality of buoyant balls 120 in the pipe string 115, theballs configured to at least one of displace a fluid mass 105 and afluid mass 150 and have a surface friction moving in a fluid(s) therein.The column of buoyant balls 125 is entrained in a fluid 150 in the outerpipe 135 or annulus 130, the entrained buoyant balls 120 are configuredto enable a pressure differential in the pipe string or inner pipe 115with respect to the pressure in the reservoir and lift the entrainmentvia the pipe string or inner pipe 115 to the earth's surface 110. Thesystem 800 additionally includes a column 125 of the buoyant balls 120in the annulus 130 or outer pipe 135, an aggregate weight of the balls120 in the column 125 configured to entrain the balls 120 into a fluid105 in an pipe string or inner pipe 115. A ball reservoir 140 and arecovery reservoir 145 are also depicted.

Returning to FIG. 8, the buoyant balls 120 depicted in the ballreservoir 140 and in the outer pipe 135 may be controlled on entrytherein in order to uniformly entrain the balls in the first fluid 150.The first fluid 150 may be a hydrocarbon mixture of water and productionby-products according to recovery demands and recycling methodsemployed. The second fluid 105 may be a petroleum fluid comprising oiland some hydrocarbon by-products according to the natural composition ofthe reservoir. The balls 120 therefore may be throttled and may bedumped according to production schedules and flow rates required via apredetermined and controlled rise velocity of the buoyant balls asdisclosed herein. The buoyant balls 120 may therefore be introduced intothe ball reservoir 140 entrained in the fluid 105 or the balls may beintroduced separately into the ball reservoir 140 and entrained in thefluid 150 in the ball reservoir 140 under a pressure generated by apump.

In any case, the fluid 105 or 150 may fill any space between and aroundthe buoyant balls in the column 125 or in the annulus 130 such that anintroduction of an additional buoyant ball at the top of the column maypush and otherwise eject a buoyant ball at the bottom of the column 125into the pipe string or inner pipe 115. Likewise, an introduction of anadditional buoyant ball 120 into the ball reservoir 140 when filled withentrainment comprising buoyant balls 120 and fluid(s) 150 may push andotherwise eject or release a buoyant ball 120 at the bottom of thecolumn 125 into the inner pipe or pipe string 115. A water content 150of the first fluid separates therefrom and sinks at a bottom of theouter pipe based on a higher mass density than a petroleum content 105thereof in combination with the petroleum in the reservoir and in theinner pipe drill string 115.

The density of the buoyant balls depicted in the column 125 is not meantto limit the present disclosure which includes embodiments of higherdensity and lower density. Therefore, the density of the buoyant ballsentrained in the first fluid 150 and a subsequent rise velocity thereofmay be pre-determined by the petroleum production rate desired and thedynamics of the hydrocarbon reservoir being pumped and the efficiency ofthe mechanisms and methods disclosed herein. Also, the pressure that maybe used to entrain the buoyant balls in the fluid 150 may bepredetermined. The entrainment trajectory depicted in recovery reservoir145 is not intended to limit the claims of the present disclosure whichmay include pressures above and below the pressure depicted by thetrajectory of the entrainment into the recovery reservoir 145.

An embodiment of the disclosed hydrocarbon lift system may furthercomprise a predetermined ratio greater than one of a mass density of thefirst fluid to a mass density of the second fluid. Also, an increase inpetroleum production from the reservoir may be based on an increase in acontrolled rise velocity of the buoyant balls and the second fluid viaan increase in the ratio of the mass density of the first fluid to themass density of the second fluid greater than one.

FIG. 9 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising a second annulus and a space for buoyant ballreturn to the earth's surface with lifted petroleum in accordance withan embodiment of the present disclosure. Reference numbers which referto the same or similar components and limitations of other figures mayshare the same reference numbers with those of the present figure. Also,similar and same components and limitations not given reference numbersin the present figure may share the same reference numbers with thosepresented in other figures. The system comprises a well bore 205 and asecond annulus 210 formed between the well bore 205 and the outer pipe135 (also known as the ‘outer bore pipe’ in descriptions of otherfigures) within the well bore 205. Seals 215 at the top and the bottomof the second annulus 210 with respect to the earth's surface seal offthe second annulus to fluid flow therein in order to preserve theoriginal well bore and the outer pipe. Stripper wells may haveperforations that may allow hydrocarbons into the surrounding earth. Theseals 215 preclude any fluid flow through such perforations and give ameasure of assurance to environmental concerns and government agenciesthat the disclosed system will not cause contamination to theenvironment and aquifers. The space created within the outer pipe 135opens up an area for a pipe string or a coil tubing.

An embodiment of the system depicted in FIG. 9 is claimed wherein theinner pipe is a continuous coil tubing configured to be pushed into theouter pipe from the earth's surface and down into or near the reservoir.The coil tubing is a very long metal pipe, normally 1″ to 3.25″ indiameter which is supplied spooled on a large reel. The coil tubing maybe used sometimes as production tubing in depleted wells. Coiled tubingis often used to carry out operations similar to wirelining. The mainbenefits over wireline are the ability to pump chemicals through thecoil and the ability to push it into the hole rather than relying ongravity feed. Coil tubing pumping can be fairly self-contained, almost aclosed system, since the tube is continuous instead of a jointed pipe.The coil tubing therefore may be used as a return or as a string pipe inthe disclosed system.

FIG. 10 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising a second and a first annulus and an inner pipefor buoyant ball return to the earth's surface with lifted petroleum inaccordance with an embodiment of the present disclosure. Referencenumbers which refer to the same or similar components and limitations ofother figures may share the same reference numbers with those of thepresent figure. Also, similar and same components and limitations notgiven reference numbers in the present figure may share the samereference numbers with those presented in other figures. The systemcomprises a well bore 205 and a second annulus 210 formed between thewell bore 205 and the outer pipe 135 (also known as the ‘outer borepipe’ in descriptions of other figures) within the well bore 205, and afirst annulus 130 formed between the outer pipe 135 and the inner pipe115 (also known as the ‘pipe string’ in descriptions of other figures).Seals 215 at the top and the bottom of the second annulus 210 withrespect to the earth's surface seal off the second annulus to fluid flowtherein in order to preserve the original well bore and the outer pipe.Stripper wells may have perforations that may allow hydrocarbons intothe surrounding earth. The seals 215 preclude any fluid flow throughsuch perforations and give a measure of assurance to environmentalconcerns and government agencies that the disclosed system will notcause contamination to the environment and aquifers. For newer wellswhere perforations are not a concern, the first annulus or the secondannulus or both annuli may be used for production and recovery asdisclosed herein. Some disclosed systems include only the second annulus210 and the seals or packers 215 at the top and bottom ends thereof.

The system of FIG. 10 also includes a plurality of buoyant ballsentrained in a first fluid in one of the annuli, the balls configured toat least one of displace a fluid mass and have a surface friction movingin the first fluid therein. The system additionally includes anentrained column of the buoyant balls in the first fluid in one of theannuli, an aggregate weight thereof configured to entrain the balls andthe first fluid into a second fluid in the inner pipe 115. The annulusfor the buoyant ball entrainment may be the second annulus 210 or thefirst annulus 130. The well bore 205 may be encased in one of cement anda metallic pipe and a combination thereof and any other materials knownto those learned in the art.

FIG. 11 is a cross sectional view of a buoyant ball assisted hydrocarbonlift system comprising a second and a first annulus for buoyant ballreturn to the earth's surface with lifted petroleum in accordance withan embodiment of the present disclosure. Reference numbers which referto the same or similar components and limitations of other figures mayshare the same reference numbers with those of the present figure. Also,similar and same components and limitations not given reference numbersin the present figure may share the same reference numbers with thosepresented in other figures. The system comprises a well bore 205 and asecond annulus 210 formed between the well bore 205 and the outer pipe135 (also known as the ‘outer bore pipe’ in descriptions of otherfigures) within the well bore 205, and a first annulus 130 formedbetween the outer pipe 135 and the inner pipe 115 (also known as the‘pipe string’ in descriptions of other figures). Seals 215 at the topand the bottom of the second annulus 210 with respect to the earth'ssurface seal off the second annulus to fluid flow therein in order topreserve the original well bore and the outer pipe. An depicted systemalso includes the column of buoyant balls entrained in the first fluidvice versa disposed in the inner pipe. Also, the entrained buoyant ballsin the second fluid are vice versa disposed in the second annulus toenable a pressure differential in the second annulus with respect to theinner pipe to lift the buoyant balls and the second fluid to the earth'ssurface.

An embodiment of the disclosed system includes a pump attached to theouter pipe, the pump configured to pressurize the first fluid and thebuoyant balls entrained therein through the outer pipe. Also, acontrolled rise velocity of the buoyant balls relative to the firstfluid may be predetermined by a specific gravity of each buoyant ballentrained in the first fluid and a variable diameter of each buoyantball therein, the diameter variable based on a porosity and ahydrocarbon absorption and expansion into a diameter of the buoyantballs. In other words, the system includes a plurality of annuli formedbetween an encased well bore and an outer pipe within the well bore andan inner pipe drill string within the outer pipe. The system alsoincludes a column of a plurality of buoyant balls in the plurality ofannuli, a weight thereof configured to entrain the buoyant balls into afirst fluid in the plurality of annuli and an aggregate weight of thecolumn and the first fluid configured to entrain the column and firstfluid into a second fluid in the inner pipe drill string. The systemfurther includes an increased rise velocity of the buoyant balls and thesecond fluid to the surface via the inner pipe drill string based on anincrease in a radius of each buoyant ball in relation to a smallerradius and a slower velocity of the buoyant balls in the first fluid.

FIG. 12 is a block diagram of a method for a triwall buoyant ballassisted hydrocarbon lift to the earth's surface in accordance with anembodiment of the present disclosure. The method includes 410 forming aplurality of annuli between an encased well bore and an outer pipewithin the well bore and an inner pipe within the outer pipe, a firstannulus defined between the inner pipe and the outer pipe and a secondannulus defined between the encased well bore and the outer pipe. Themethod also includes 420 forming a seal on the second annulus on atleast a top end and a bottom end thereof with respect to the earth'ssurface, the seal configured to prevent a fluid flow there through andpreserve a condition of the well bore and the outer pipe. The methodadditionally includes 430 creating a column of a plurality of buoyantballs in the plurality of annuli, a weight thereof configured to entrainthe buoyant balls into a first fluid in the plurality of annuli. Themethod further includes 440 entraining the column of buoyant balls andthe first fluid in the second annulus via the weight thereof andentraining the buoyant balls and the first fluid into a second fluid inthe inner pipe via an aggregate weight thereof. The method yet includes450 creating a hydrostatic pressure differential in the inner pipe withrespect to the reservoir via the buoyant balls, the pressure configuredto lift a fluid in the inner pipe to the surface.

An embodiment of the method for lifting petroleum fluids, furtherincludes opening and closing a dynamic seal configured on at least oneof a top end and a bottom end of the second annulus with respect to theearth's surface, the opening and closing of the dynamic seal configuredto be remotely controlled or based on a pressure differential between asecond fluid pressure in the inner pipe and a first fluid pressure inthe outer pipe.

Although the operations of the method(s) herein are shown and describedin a particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operations may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be implemented in anintermittent and/or alternating manner.

While the forgoing examples are illustrative of the principles of thepresent disclosure in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the disclosure be limited, except as by the specificationand claims set forth herein.

What is claimed is:
 1. A hydrocarbon lift system for lifting petroleumfluid(s) from an enclosed subterranean reservoir to the earth's surface,the system comprising: a second annulus formed between a well bore andan outer pipe within the well bore, and a first annulus formed betweenthe outer pipe and an inner pipe; and a seal formed on the secondannulus on at least a top end and a bottom end thereof with respect tothe earth's surface, the seal configured to prevent a fluid flow therethrough and preserve a condition of the well bore and the outer pipe. 2.The hydrocarbon lift system of claim 1, further comprising a pluralityof buoyant balls entrained in a first fluid in one of the annuli, theballs configured to at least one of displace a fluid mass and have asurface friction moving in the first fluid therein; and an entrainedcolumn of the buoyant balls in the first fluid in one of the annuli, anaggregate weight thereof configured to entrain the balls and the firstfluid into a second fluid in the inner pipe.
 3. The hydrocarbon liftsystem of claim 1, further comprising a pressure differential in theinner pipe with respect to the reservoir via the entrained buoyantballs, the pressure differential configured to lift the second fluid andthe entrained balls via the inner pipe to enhance petroleum productionto the surface.
 4. The hydrocarbon lift system of claim 1, wherein theinner pipe is a continuous coil tubing configured to be pushed into theouter pipe and into the reservoir.
 5. The hydrocarbon lift system ofclaim 2, wherein the one of the annuli is the first annulus, primarilyin stripping wells.
 6. The hydrocarbon lift system of claim 2, whereinthe one of the annuli is the second annulus, primarily in newer andhigher producing wells.
 7. The hydrocarbon lift system of claim 1,further comprising a packer disposed on the second annulus on a top endand a bottom end thereof with respect to the earth's surface, the packerconfigured to prevent a fluid flow there through and preserve acondition of the well bore and the outer pipe.
 8. The hydrocarbon liftsystem of claim 2, further comprising a pump attached to the outer pipe,the pump configured to pressurize the first fluid and the buoyant ballsentrained therein through the outer pipe.
 9. The hydrocarbon lift systemof claim 2, wherein the column of buoyant balls entrained in the firstfluid is vice versa disposed in the inner pipe and the entrained buoyantballs in the second fluid are vice versa disposed in the second annulusto enable a pressure differential in the second annulus with respect tothe inner pipe to lift the buoyant balls and the second fluid to theearth's surface.
 10. The hydrocarbon lift system of claim 2, wherein thecolumn of buoyant balls forms under an aggregate weight of the buoyantballs and the first fluid and extends from a bottom end of the outerpipe to a column height greater than a height of the first fluid in theouter pipe.
 11. The hydrocarbon lift system of claim 2, furthercomprising a controlled rise velocity of the buoyant balls relative tothe first fluid predetermined by a specific gravity of each buoyant ballentrained in the first fluid and a variable diameter of each buoyantball therein.
 12. A hydrocarbon lift system for lifting petroleumfluid(s) from an enclosed subterranean reservoir to the earth's surface,the system comprising: a plurality of annuli formed between an encasedwell bore and an outer pipe within the well bore and an inner pipe drillstring within the outer pipe; a column of a plurality of buoyant ballsin the plurality of annuli, a weight thereof configured to entrain thebuoyant balls into a first fluid in the plurality of annuli and anaggregate weight of the column and the first fluid configured to entrainthe column and first fluid into a second fluid in the inner pipe drillstring; and an increased rise velocity of the buoyant balls and thesecond fluid to the surface via the inner pipe drill string based on anincrease in a radius of each buoyant ball in relation to a smallerradius and a slower velocity of the buoyant balls in the first fluid.13. The hydrocarbon lift system of claim 12, wherein the plurality ofannuli comprises both a second annulus formed between the encased wellbore and the outer pipe and a first annulus formed between the outerpipe and the inner pipe.
 14. The hydrocarbon lift system of claim 12,further comprising a dynamic seal on at least one of a top end and abottom end of the second annulus with respect to the earth's surface,the dynamic seal configured to be remotely controllable.
 15. Thehydrocarbon lift system of claim 12, wherein the mass density of thefirst fluid is comprised of a predetermined water and petroleum mixtureand is higher in mass density than the mass density of the second fluidcomprised of petroleum from the reservoir and petroleum separated fromthe first fluid wherein the buoyant balls have a controlled risevelocity within the second fluid in the inner pipe drill string.
 16. Thehydrocarbon lift system of claim 12, wherein a ratio of water topetroleum in the first fluid is greater than one and a ratio of water topetroleum in the second fluid is less than one to enable a positive risevelocity of the buoyant balls in the second fluid via a constant radiusof the buoyant balls.
 17. The hydrocarbon lift system of claim 12,further comprising a buoyant ball specific gravity of 0.23 plus or minusa 10 percent tolerance and an approximate 0.64 to 2.54 centimeters (0.25inch to 1 inches) variable diameter for rise velocities between 3.56cm/sec (1.4 in/sec) up to 56.0 cm/sec (22+ inches/second).
 18. A methodfor lifting petroleum fluid(s) from an enclosed subterranean reservoirto the earth's surface, the method comprising: forming a plurality ofannuli between an encased well bore and an outer pipe within the wellbore and an inner pipe within the outer pipe, a first annulus definedbetween the inner pipe and the outer pipe and a second annulus definedbetween the encased well bore and the outer pipe; creating a column of aplurality of buoyant balls in the plurality of annuli, a weight thereofconfigured to entrain the buoyant balls into a first fluid in theplurality of annuli; and entraining the column of buoyant balls and thefirst fluid in the second annulus via the weight thereof and entrainingthe buoyant balls and the first fluid into a second fluid in the innerpipe via an aggregate weight thereof.
 19. The method for liftingpetroleum fluids of claim 18, further comprising vice versa disposingthe column of buoyant balls entrained in the first fluid to the innerpipe drill string and vice versa disposing the entrained buoyant ballsin the second fluid in the outer pipe to enable a pressure differentialin the outer pipe with respect to the subterranean pressure to lift thebuoyant balls and the second fluid to the earth's surface.
 20. Themethod for lifting petroleum fluids of claim 18, further comprisingforming a seal on the second annulus on at least a top end and a bottomend thereof with respect to the earth's surface, the seal configured toprevent a fluid flow there through and preserve a condition of the wellbore and the outer pipe.